Presiding Judge Alessandro Nencini read out the five-page e-mail written in Italian and sent from the US, where Knox now lives. He noted that the e-mail, presented by Knox's lawyers, was not a normal procedure in Italy. He said it highlighted Knox's absence and indicated it did not have the same legal standing as a declaration made in person.

"Who wants to speak at a trial, comes to the trial," Nencini said, adding that he had to take the word of her lawyers that the e-mail originated with Knox. "I never saw her, I don't know her."

Knox explained her absence was out of fear that she would be wrongly convicted, which she contends happened during the first trial against her and her former boyfriend, Italian Raffaele Sollecito. The case against Knox, 26, and Sollecito, 29, is being heard for a third time.

Knox spent four years in jail in Italy. She was permitted to return to the US in 2011 after she was acquitted on appeal - a decision overturned in March by Italy's highest court, which sent it back for a second appeals trial. Sollecito has appeared at several hearings, declaring his innocence.

"I am not in court because I am afraid. I am afraid that the vehemence of the prosecution will make an impression on you, that their smoke will get in your eyes and blind you," Knox said in the e-mail. "I am not afraid of your powers of discernment, but because the prosecution has succeeded already in convincing a court comprised of responsible and perceptive adults to convict innocent people, Raffaele and me."

She said she was following the case closely "given that my life is at stake".

Meredith Kercher, 21, was murdered in November 2007 in the apartment she shared with Knox in the picturesque Italian university town of Perugia. She had been raped, stabbed dozens of times in the face, had her throat slashed and her body left beneath a blanket in her bedroom.

This article appeared in the South China Morning Post print edition as Knox declares innocence in e-mail